A serializer/deserializer (also referred as SerDes) is usually used in high speed communications. In the SerDes application, a transmitter (Tx) converts a parallel data into a serial data and then the serial data is transmitted to a receiver (Rx) according to a differential signal (D+, D−).
Generally, a front end circuit of the receiver (Rx) comprises a data clock recovery circuit. The data clock recovery circuit generates a recovered data and a recovered clock according to the differential signal (D+, D−) from the transmitter (Tx). A rear end controller of the receiver (Rx) samples the recovered data according to the recovered clock.
Moreover, the front end circuit of the receiver (Rx) further comprises an analog detection circuit. The analog detection circuit generates a receiver loss of signal (also referred as a RXLOS signal) according to the differential signal (D+, D−) and transmits the RXLOS signal to the rear end controller.
Generally, the RXLOS signal outputted from the front end circuit of the receiver (Rx) is a digital data indicating whether a usable data presence status or a usable data absence status is detected. Consequently, the rear end controller processes the recovered data according to the RXLOS signal. For example, if the analog detection circuit judges that the receiver is in the usable data absence status according to the differential signal (D+, D−), the RXLOS signal outputted from the analog detection circuit has a first logic level (e.g., a high level). Whereas, if the analog detection circuit judges that the receiver is in the usable data presence status according to the differential signal (D+, D−), the RXLOS signal outputted from the analog detection circuit has a second logic level (e.g., a low level).
However, in the conventional high-speed SerDes architecture, the analog detection circuit of the receiver (Rx) cannot stably generate the RXLOS signal. Consequently, the RXLOS signal contains many glitches. When the RXLOS signal containing glitches is received by the rear end controller, the RXLOS signal may lead to erroneous operation of the rear end controller. Under this circumstance, the operation of the SerDes is very unstable.